FUEL CELL VALVE CONFIGURATION

An illustrative example fuel cell reactant flow control valve assembly includes a pneumatic valve configured to allow reactant flow when the pneumatic valve is in an open condition and to prevent reactant flow when the pneumatic valve is in a closed condition. A control valve selectively allows a pressure of the reactant to provide pneumatic pressure to maintain the pneumatic valve in the open condition. The control valve selectively vents the pneumatic pressure reservoir to control a rate at which the pneumatic pressure decreases and a rate at which the pneumatic valve changes from the open condition to the closed condition.